There is widespread recognition of the effects of aging. Bodily functions slow down and sometimes body parts malfunction. In the gastrointestinal system, food moves down the esophagus through the esophageal sphincter muscle into the stomach and from there enters the first parts of the small intestine, e.g. the duodenum and the jejunum, then through the final portion of the small intestine, called the ileum; and then through the colon. The unabsorbed remaining portion of the food is evacuated through the rectum.
During this process, nourishment is absorbed into the blood stream, which in turn is cleansed of liquid waste by the kidneys with the resulting release of urine into the bladder for evacuation through the urethra. The pancreas, which is located below the stomach, introduces stomach-acid-neutralizing bicarbonate, insulin, etc. into the duodenum. A series of mostly involuntary nerve sensors control this process. This includes the control of both band-like and longitudinal muscular action to produce movement of solids through the intestines. This function is much like an earth worm's method of propulsion. Villi lining the intestines pick up nutrients, liquids, and enzymes for movement into the vascular system. In the vascular system, however, blood vessels can also lose their flexibility and size with age, with resulting decrease in bodily function.
Urine release is controlled by the urethral sphincter muscles, which often become weak with age, causing urine leakage, and incontinence. Sleep is interrupted by frequent trips to the bathroom, along with a daytime need for wearing adult diapers or an external reservoir. Medications may help, but they have possible side effects and often produce only short term results because of bodily acclimation.
Fecal matter release is controlled by the anal sphincter muscles, which can become weak with age, resulting in at least some degree of fecal incontinence.
The esophageal sphincter at the cardiac end of the stomach controls prevention of stomach acid backing up into the esophagus, which would otherwise cause lesions and “heart burn” or worse. This sphincter often becomes weak and stays open with age. Also, the esophagus gets narrower with age making it sometimes difficult for food to readily pass through it.
Further, as the body ages, processed food typically moves more slowly through the intestines and stays in the gastrointestinal system longer. The result is greater absorption of nutrients from the same quantity of food and deterioration of the quality of the food moving through the gastrointestinal tract. This results in greater weight gain for the same amount of food eaten, possible flatulence, and possible other intestinal maladies that can be absorbed and passed on to the vascular system for delivery throughout the body. This could be a source of disease and malfunction of many organs, including the heart, the brain, the skin, the eyes, and the lungs.